(***********************************************************************)
(*                             OCamldoc                                *)
(*                                                                     *)
(*            Maxence Guesdon, projet Cristal, INRIA Rocquencourt      *)
(*                                                                     *)
(*  Copyright 2001 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the Q Public License version 1.0.               *)
(*                                                                     *)
(***********************************************************************)

(* $Id$ *)

exception Text_syntax of int * int * string (* line, char, string *)

open Odoc_types

module Texter =
  struct
    (* builds a text structure from a string. *)
    let text_of_string s =
      let lexbuf = Lexing.from_string s in
      try
        Odoc_text_lexer.init ();
        Odoc_text_parser.main Odoc_text_lexer.main lexbuf
      with
        _ ->
          raise (Text_syntax (!Odoc_text_lexer.line_number,
                              !Odoc_text_lexer.char_number,
                              s)
                )

    let count s c =
      let count = ref 0 in
      for i = 0 to String.length s - 1 do
	if s.[i] = c then incr count
      done;
      !count

    let escape_n s c n =
      let remain = ref n in
      let len = String.length s in
      let b = Buffer.create (len + n) in
      for i = 0 to len - 1 do
	if s.[i] = c && !remain > 0 then
	  (
	   Printf.bprintf b "\\%c" c;
	   decr remain
	  )
	else
	  Buffer.add_char b s.[i]
      done;
      Buffer.contents b

    let escape_code s =
      let open_brackets = count s '[' in
      let close_brackets = count s ']' in
      if open_brackets > close_brackets then
	escape_n s '[' (open_brackets - close_brackets)
      else
	if close_brackets > open_brackets then
	  escape_n s ']' (close_brackets - open_brackets)
	else
	  s

    let escape_raw s =
      let len = String.length s in
      let b = Buffer.create len in
      for i = 0 to len - 1 do
	match s.[i] with
	  '[' | ']' | '{' | '}' ->
	    Printf.bprintf b "\\%c" s.[i]
	| c ->
	    Buffer.add_char b c
      done;
      Buffer.contents b

    let p = Printf.bprintf

    let rec p_text b t =
      List.iter (p_text_element b) t

    and p_list b l =
      List.iter
	(fun t -> p b "{- " ; p_text b t ; p b "}\n")
	l

    and p_text_element b = function
      | Raw s -> p b "%s" (escape_raw s)
      | Code s -> p b "[%s]" (escape_code s)
      | CodePre s -> p b "{[%s]}" s
      | Verbatim s -> p b "{v %s v}" s
      | Bold t -> p b "{b " ; p_text b t ; p b "}"
      | Italic t -> p b "{i " ; p_text b t ; p b "}"
      | Emphasize t -> p b "{e " ; p_text b t ; p b "}"
      | Center t -> p b "{C " ; p_text b t ; p b "}"
      | Left t -> p b "{L " ; p_text b t ; p b "}"
      | Right t -> p b "{R " ; p_text b t ; p b "}"
      | List l -> p b "{ul\n"; p_list b l; p b "}"
      | Enum l -> p b "{ol\n"; p_list b l; p b "}"
      | Newline -> p b "\n"
      | Block  t -> p_text b t
      | Title (n, l_opt, t) ->
	  p b "{%d%s "
	    n
	    (match l_opt with
	      None -> ""
	    | Some s -> ":"^s
	    );
	  p_text b t ;
	  p b "}"
      | Latex s -> p b "{%% %s%%}" s
      | Link (s,t) ->
	  p b "{{:%s}" s;
	  p_text b t ;
	  p b "}"
      | Ref (s,None) ->
	  p b "{!%s}" s
      |	Ref (s, Some k) ->
	  (
	   let sk = match k with
	     RK_module -> "module"
	   | RK_module_type -> "modtype"
	   | RK_class -> "class"
	   | RK_class_type -> "classtype"
	   | RK_value -> "val"
	   | RK_type -> "type"
	   | RK_exception -> "exception"
	   | RK_attribute -> "attribute"
	   | RK_method -> "method"
	   | RK_section _ -> "section"
	   in
	   p b "{!%s:%s}" sk s
	  )
      | Superscript t -> p b "{^" ; p_text b t ; p b "}"
      | Subscript t -> p b "{_" ; p_text b t ; p b "}"
      | Module_list l ->
	  p b "{!modules:";
	  List.iter (fun s -> p b " %s" s) l;
	  p b "}"
      |	Index_list ->
	  p b "{!indexlist}"
      |	Custom (s,t) ->
	  p b "{%s " s;
	  p_text b t;
	  p b "}"

    let string_of_text s =
      let b = Buffer.create 256 in
      p_text b s;
      Buffer.contents b

  end
